PHP的一個完美GIF等比縮放類,附帶去除縮放黑背景_php執行個體

現在寫東西都喜歡封裝成類.....大家調用一下就行了..我就不說怎麼調用了

複製代碼 代碼如下:class resize_image{
private $o_img_width;//原映像寬度
private $o_img_height;//原映像高度
private $n_img_width;//新映像寬度
private $n_img_height;//新映像高度
private $o_img_file;//原影像檔
private $o_img_source;//原映像資源
private $n_img_file;//新映像資源
private $n_img_source;//新映像資源
private $o_to_n_per=0.5;//映像縮放比

//初始化內部變數
function __construct($oldfile,$newfile){
list($width,$height)=getimagesize($oldfile);
$this->o_img_file=$oldfile;
$this->o_img_width=$width;
$this->o_img_height=$height;
$this->n_img_file=$newfile;
}

//等比例縮放並且解決GIF透明色為黑色背景的問題
function get_resize_scaling_img(){
$this->n_img_width=$this->o_img_width*$this->o_to_n_per;
$this->n_img_height=$this->o_img_height*$this->o_to_n_per;
//等比例縮放圖片(演算法)
if ( $this->n_img_width && ( $this->o_img_width <$this->o_img_height))
{
$this->n_img_width = ( $this->n_img_height/$this->o_img_height) * $this->o_img_width;
}
else
{
$this->n_img_height = ($this->n_img_width / $this->o_img_width) * $this->o_img_height;
}
$this->o_img_source=imagecreatefromgif($this->o_img_file);
//建立一個等比例縮放大小的畫布
$this->n_img_source=imagecreatetruecolor($this->o_img_width,$this->n_img_height);

//美化:去除黑色不透明背景
$trans_init=imagecolortransparent($this->o_img_source);
//尋找透明色並且判斷是否在總顏色中
if($trans_init>=0 && $trans_init < imagecolorstotal($this->o_img_source)){
//如果在的話則搜尋這個顏色的RGB色相
$trans_index=imagecolorsforindex($this->o_img_source,$trans_init);
//找到之後就建立這樣一個顏色
$trans_new=imagecolorallocate($this->n_img_source,$trans_index["red"],$trans_index["green"],$trans_index["blue"]);
//然後我們用這個顏色去填充新的映像
imagefill($this->n_img_source,0,0,$trans_new);
//然後我們在把填充色設定為透明
imagecolortransparent($this->n_img_source,$trans_new);
}
//拷貝原映像到新畫板上
imagecopyresized($this->n_img_source,$this->o_img_source,0,0,0,0,$this->n_img_width,$this->n_img_height,$this->o_img_width,$this->o_img_height);
return $this->n_img_source;
}
//最終銷毀資源
function __destruct(){
imagedestroy($this->o_img_source);
imagedestroy($this->n_img_source);

}

}

說明:因為先前沒想那麼多所以聲明了很多私人的內部變數以便調用...程式看起來很笨拙啊......

